The present invention relates to an external storage device connected to electronic equipment through a cable and an entertainment system including the external storage device.
In electronic equipment such as a personal computer or an entertainment device, an external hard disk drive is employed. The external hard disk drive typically has the same structure as that of a hard disk drive internally mounted in the electronic equipment. The main unit of the hard disk drive is covered with a metal sheet to control EMI (Electromagnetic Interference), and is then housed in a case fabricated of a resin. The external hard disk drive is connected to the electronic equipment such as a computer through a cable compatible with the SCSI (Small Computer System Interface) standards, and is thus used as a storage device for the electronic equipment.
Such an external hard disk drive and the main unit of a hard disk drive internally mounted in the electronic equipment are set up for a variety of functions in accordance with the specifications of the electronic equipment and the standards applicable thereto. Specifically, the hard disk drive is set up for an intended function by electrically shorting a plurality of jumper pins exposed from the end face of the hard disk drive main unit.
In setting an intended function of the main unit of the external hard disk drive to make it compatible with intended electronic equipment, the external hard disk drive must be opened (or disassembled) to short jumper pins in the hard disk drive main unit with a connector. This step makes a setup procedure troublesome.
It may be contemplated that jumper pins are exposed externally. However, if a surge current due to static flows into a disk as a storage area, the storage function of the hard disk drive may be adversely affected.
Accordingly, it is an object of the present invention to provide an external storage device which is connected to electronic equipment through a cable and is easily set up for a function of the main unit of the external storage device.
An external storage device of the present invention in one aspect is connected to electronic equipment through a cable, and includes a storage device main unit and a switching unit for selecting functions of the storage device main unit.
An entertainment system of the present invention in another aspect includes an entertainment device, and an external storage device connected to the entertainment device through a cable, wherein the external storage device includes a storage device main unit and a switching unit for selecting functions of the storage device main unit.
The storage device main unit is set up for functions by shorting jumper pins (or by connecting jumper pins with each other). The functions to be set include (1) a master-slave selection function for selecting whether the storage main unit works in a master boot mode or in a slave boot mode, (2) a cable selection function for selecting a mast boot mode or a slave boot mode depending on the position of an external storage device in a line when a plurality of storage device main units is connected in a cascade connection through a series of cables, (3) a storage capacity setting function to forcibly set the storage capacity of the storage device main unit to a predetermined size, and (4) a standby selection function for selecting whether the startup mode (i.e., the mode of when the electronic equipment (an entertainment device) is switched on) of the storage device is a standby mode or not.
In a preferred embodiment of the present invention, a switch is externally exposed out of a case of the storage device main unit. The user thus can freely set the function of the external storage device by simply operating the switch. This arrangement eliminates a troublesome step for setting the function of the storage device, such as opening (or disassembling) the case of the storage device. Since jumper pins are not externally exposed out of the storage main unit, its function is changed without any adverse effect such as static charge on the storage main unit.
The above-mentioned switch preferably switches the mode of the storage main unit between a master boot mode and a slave boot mode. When a plurality of storage devices is connected to the electronic equipment (the entertainment device), it is necessary to select one storage device to retrieve information therefrom at the startup. By enabling selection between the mater boot mode and the slave boot mode, the mater-slave setting is flexibly performed. In the electronic equipment such as the entertainment device having no internal storage device, an external storage device must work in the master boot mode. The switch is very useful in such a case.
An interface of the storage device with the electronic equipment is preferably compliant with the ATA (AT Attachment) standards. The interfaces between the external storage device and the electronic equipment are conventionally compliant with the SCSI (Small Computer System Interface) standards, the IEEE (Institute of Electrical and Electronic Engineers) standards, etc. The ATA standards have been applied to the dedicated internal components. In accordance with the conventional SCSI standards, a signal input through an SCSI cable from the electronic equipment is converted into a signal compatible with the ATA standards by an IC (Integrated Circuit) in the external storage device and is then fed into the storage device main unit. With an ATA-compliant interface, a signal is directly communicated between the electronic equipment and the external storage device without being converted by an IC. The number of the component of the external storage device is thus minimized, and the manufacturing cost of the external storage device is reduced.
The switch and the storage device main unit are preferably connected to each other with a surge protection circuit connected therebetween. The surge protection circuit includes a varistor connected between a switching line for an on/off operation of the switch and a ground line. With such a surge protection circuit, a surge current drains to ground through the varistor when the surge current due to a static, which occurs by operating the switch, flows into the switching line. The storage device main unit is thus reliably prevented from being affected by the surge current.